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Description
Ecolabels are the main driving force of consumer knowledge in the realm of sustainable product purchasing. While ecolabels strive to improve consumer's purchasing decisions, they have overwhelmed the market, leaving consumers confused and distrustful of what each label means. This study attempts to validate and understand environmental concerns commonly found in ecolabel criteria and the implications they have within the life cycle of a product. A life cycle assessment (LCA) case study of cosmetic products is used in comparison with current ecolabel program criteria to assess whether or not ecolabels are effectively driving environmental improvements in high impact areas throughout the life cycle of a product. Focus is placed on determining the general issues addressed by ecolabelling criteria and how these issues relate to hotspots derived through a practiced scientific methodology. Through this analysis, it was determined that a majority the top performing supply chain environmental impacts are covered, in some fashion, within ecolabelling criteria, but some, such as agricultural land occupation, are covered to a lesser extent or not at all. Additional criteria are suggested to fill the gaps found in ecolabelling programs and better address the environmental impacts most pertinent to the supply chain. Ecolabels have also been found to have a broader coverage then what can currently be addressed using LCA. The results of this analysis have led to a set of recommendations for furthering the integration between ecolabels and life cycle tools.
ContributorsBernardo, Melissa (Author) / Dooley, Kevin (Thesis advisor) / Chester, Mikhail Vin (Thesis advisor) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2012
Description
Sustainable food systems have been studied extensively in recent times and the Food-Energy-Water (FEW) nexus framework has been one of the most common frameworks used. The dissertation intends to examine and quantitatively model the food system interaction with the energy system and the water system. Traditional FEW nexus studies have focused on food production alone. While this approach is informative, it is insufficient since food is extensively traded. Various food miles studies have highlighted the extensive virtual energy and virtual water footprint of food. This highlights the need for transport, and storage needs to be considered as part of the FEW framework. The Life cycle assessment (LCA) framework is the best available option to estimate the net energy and water exchange between the food, energy, and water systems. Climate plays an important role in food production as well as food preservation. Crops are very sensitive to temperature changes and it directly impacts a crop’s productivity. Changing temperatures directly impact crop productivity, and water demand. It is important to explore the feasibility of mitigation measures to keep in check increasing agricultural water demands. Conservation technologies may be able to provide the necessary energy and water savings. Even under varying climates it might be possible to meet demand for food through trade. The complex trade network might have the capacity to compensate for the produce lost due to climate change, and hence needs to be established. Re-visualizing the FEW nexus from the consumption perspective would better inform policy on exchange of constrained resources as well as carbon footprints. This puts the FEW nexus research space a step towards recreating the FEW nexus as a network of networks, that is, FEW-e (FEW exchange) nexus.
ContributorsNatarajan, Mukunth (Author) / Chester, Mikhail Vin (Thesis advisor) / Lobo, Jose (Committee member) / Ruddell, Benjamin (Committee member) / Fraser, Andrew (Committee member) / Arizona State University (Publisher)
Created2019
Description
Carbon capture and sequestration (CCS) is one of the important mitigation options for climate change. Numerous technologies to capture carbon dioxide (CO2) are in development but currently, capture using amines is the predominant technology. When the flue gas reacts with amines (Monoethanaloamine) the CO2 is absorbed into the solution and forms an intermediate product which then releases CO2 at higher temperature. The high temperature necessary to strip CO2 is provided by steam extracted from the powerplant thus reducing the net output of the powerplant by 25% to 35%. The reduction in electricity output for the same input of coal increases the emissions factor of Nitrogen Oxides, Mercury, Particulate matter, Ammonia, Volatile organic compounds for the same unit of electricity produced. The thesis questions if this tradeoff between CO2 and other emissions is beneficial or not. Three different methodologies, Life Cycle Assessment, Valuation models and cost benefit analysis are used to identify if there is a net benefit to the society on implementation of CCS to a Pulverized coal powerplant. These methodologies include the benefits due to reduction of CO2 and the disbenefits due to the increase of other emissions. The life cycle assessment using ecoindicator'99 methodology shows the CCS is not beneficial under Hierarchical and Egalitarian perspective. The valuation model shows that the inclusion of the other emissions reduces the benefit associated with CCS. For a lower CO2 price the valuation model shows that CCS is detrimental to the environment. The cost benefit analysis shows that a CO2 price of at least $80/tCO2 is required for the cost benefit ratio to be 1. The methodology integrates Montecarlo simulation to characterize the uncertainties associated with the valuation models.
ContributorsSekar, Ashok (Author) / Williams, Eric (Thesis advisor) / Chester, Mikhail Vin (Thesis advisor) / Allenby, Braden (Committee member) / Arizona State University (Publisher)
Created2012
Description
This research will utilize the energy and poverty alleviation framework to investigate a sustainable energy ecosystem for the Wakapoa indigenous community of Guyana. Five questions guide the research – 1) Is there an energy access-development nexus? 2) Can the relationships and trends between key development indicators and electricity access guide policymakers on development activities? 3) Can small-scale concentrated solar and biomass systems provide adequate electrical power to meet the Wakapoa community's domestic and commercial loads economically? 4) What added social value could be generated from the energy system as per Wakapoa context? and 5) What governance systems can be considered to facilitate a sustainable energy ecosystem? In addressing questions 1 and 2, the research collected secondary data on selected countries' key development indexes from the World Bank and Our World in Data. Datasets include the human development index, human capital index, gross domestic product per capita, gross national income per capita, and electricity access. In addressing questions 3 to 5, the research utilized the convergent research design methods, where an inclusive data collection process targeted fifty (50) community residents as survey participants. Statistical analysis of the survey data proved useful in identifying the community needs for the renewable energy system design options utilizing system advisor model (SAM) software, identifying key economic activities that can add social value to the community, and giving key insight into governance practices preferred by the community. Key findings reveal that electricity access exerts a strong and moderate influence on key development indicators, the concentrated solar power and biomass hybrid system can satisfy the electricity demand of the community at the Tier-5 level that can support many traditional and non-traditional economic activities, while key governance support functions such as the community financial aid fund and community management committee can enhance the sustainability of the various operations as well as residents' well-being and livelihood. Future research can address project financing, community productive capacity, and the marketing of goods and services to promote a sustainable energy ecosystem.
ContributorsKanhai, Mahendra N. (Author) / Chhetri, Nalini (Thesis advisor) / Dirks, Gary (Thesis advisor) / Miller, Clark (Committee member) / Stechel, Ellen (Committee member) / Arizona State University (Publisher)
Created2023
Description
There is a lack of prior research about factors and conditions relating to the underdevelopment of infrastructure on Navajo Nation, especially from a community-centered perspective. As a Diné researcher, the intersection created via the fields of Science and Technology Studies (STS), American Indian Studies (AIS), and Diné Studies creates a means by which developmental policy and futures planning can be discussed. Through qualitative inquiry, specifically cross-case analysis, oral histories, and archival review from a Diné perspective, this work establishes the relationship between roads, energy, and Information and Communication Technologies (ICTs) in the Navajo Nation in relation to the historical underdevelopment of infrastructure on the reservation, especially from 2000 to 2020. Roads and energy infrastructures make way for ICT deployments, and together, these three infrastructures shape futures planning for the Nation, including governance decisions relating to partnerships, and internal versus external development. Relationships between infrastructural efforts, past colonial practices of the United States (U.S.), and relations between the U.S. and tribes during this era shape the development of relevant expertise within Navajo Nation entities and also impact access to and uses of significant funding opportunities available via the early 21st century American Recovery and Reinvestment Act. A Diné-centered concept of care through long-term infrastructure deployment relates tribal sovereignty and Indigenous ways of knowing to Indigenous Science and Technology Studies (STS) and suggests new directions for applied Diné studies in the field of Indigenous STS.
ContributorsGeorge, Alaina Sarah (Author) / Duarte, Marisa E (Thesis advisor) / Richter, Jennifer (Thesis advisor) / Wetmore, Jameson (Committee member) / Arizona State University (Publisher)
Created2023
Description
Functioning freshwater ecosystems are widely recognized as a planetary boundary for the continued human inhabitation of our planet, but little is known about the tradeoffs at the nexus of food, energy and water. In this dissertation I explored the effects of hydrologic variability in the Lower Mekong Basin (LMB) on rice production and functional structure of fish catches. I then examined the tradeoffs at the intersection of fish and rice harvest as a function of hydrologic variability and modeled production under novel engineered hydrologic scenarios. I modeled rice production using a Multivariate Autoregressive State Space (MARSS) model and mechanistically tested for the effect of saline intrusion. I found rice production to be heterogeneously affected by hydrology; in saline afflicted areas, floods had a positive effect size on production, whereas in non-saline afflicted areas, floods had a negative effect size on production. To address hydrologic filtering of the functional structure of fish catches, I collected thousands of specimens from over 100 LMB species in collaboration with Cambodia’s Inland Fisheries Research and Development institute and the Royal University of Agriculture. LMB fishes comprise a large portion of the 1,200 known species in the basin and have historically provided a substantial amount of animal protein to 60 million people in the region. Using an RLQ, co-inertia analysis, I found four functionally relevant morphological trats that were significantly associated with hydrologic variation—mouth position, maxillary length, relative body depth, and relative head depth. These traits are associated with many of the threated species in the LMB, which make up a large portion of the 1200 known species in the basin and have historically provided a substantial amount of animal protein to 60 million people in the region. To examine the tradeoffs within food systems, I used MARSS maximum likelihood estimation to forecast fish and rice production throughout the LMB under different hydrologic scenarios. I end my dissertation with an opinion piece on NexGen Mekong Scientists, a program I started in 2020 with funding from the United States Department of State.
ContributorsHolway, Joseph Henry (Author) / Sabo, John (Thesis advisor) / Grimm, Nancy (Committee member) / Holtgrieve, Gordon (Committee member) / Winemiller, Kirk (Committee member) / Hanemann, Michael (Committee member) / Arizona State University (Publisher)
Created2024
Description
Lignocellulosic biomass represents a sustainable and abundant renewable resource with enormous potential to support large-scale bioproduction of fuels and value-added chemicals. However, efficiently converting the diverse array of substrates present in lignocellulosic hydrolysates into desired products using microbial cell factories remains challenging. Inherent regulatory mechanisms found in bacteria, coupled with metabolic constraints related to redox balance, energy production, and substrate transport, pose significant hurdles to efficient bioproduction from lignocellulosic sugars. Attempts to alleviate these constraints through purely rational engineering have been limited by the intrinsic complexity of biological systems. Adaptive laboratory evolution has emerged as a powerful complement to rational engineering efforts to develop bacterial phenotypes of industrial relevance. In this work, I explore the use of adaptive laboratory evolution and reverse engineering to improve sugar co-fermentation and the production of ethanol and succinate in E. coli. Specifically, I demonstrate that point mutations in the xylose-specific transcriptional regulator, XylR, relieve arabinose-induced repression on xylose fermentation and improves co-utilization of glucose-xylose-arabinose sugar mixtures in an ethanologenic E. coli strain. Furthermore, in Chapter 3 of this dissertation, I present the identification of novel mutations in pdhR, lpd, and agaR that contribute to enhanced anaerobic succinate production. The value of these mutations is demonstrated by their ability to significantly improve succinate yields in engineered E. coli succinate strains, highlighting the potential for ALE to uncover beneficial genetic changes that can be harnessed to optimize microbial production processes for industrial applications.
ContributorsMartinez, Rodrigo (Author) / Wang, Xuan (Thesis advisor) / Nielsen, David R (Committee member) / Geiler-Samerotte, Kerry (Committee member) / Varman, Arul M (Committee member) / Arizona State University (Publisher)
Created2024
Description
Modern and future computer architectures will feature hyper-efficient and low-latency processing elements dedicated to a specific purpose.In a process known as pre-silicon design, computer architects design a customized piece of hardware, called a domain-specific architecture (DSA), to support the high performance and efficiency of a target group of computer programs.
Each program contains sections of code called "tasks" whose characteristics may be exploited for hyper-efficient and low-latency execution on specialized processors called processing elements (PE).
Architects design PEs toward those tasks, enabling DSAs to deliver magnitudes of performance and energy-efficiency advantages over general-purpose, scalar processors.
After the pre-silicon design phase of a DSA is the post-silicon design phase, where application designers map other and novel computer programs for high performance on that DSA.
To realize the performance and energy benefits of that DSA, each computer program must realize the PEs of that DSA.
Unfortunately, refactoring applications to exploit the PEs of a DSA is difficult.
Application and architectural experts (whose expertise is in low supply) must manually structure each application toward their target DSA.
Furthermore, open-source and legacy code called code-from-the-wild (CFTW), often lack the structure required to compile applications toward DSAs, requiring manual refactoring and creating a barrier between DSAs and the broader software engineering community.
Finally, manual application structuring techniques do not scale to novel applications and architectures.
This thesis argues that automating the process of structuring computer programs for transformation and optimization toward DSAs is essential to the widespread adoption and utilization of DSAs. Existing methods to extract the structure from CFTW both capture unimportant code and miss critical code for acceleration because they rely on code frequency.Further, they rely on static information to find communication patterns between them.
To address the challenge of localizing the acceleration candidates and finding their communication among each other, this thesis presents Cyclebite.
Cyclebite extracts coarse-grained tasks (CGTs) from CFTW by detecting CGT candidates in the dynamic execution profile of the application.
Then, Cyclebite localizes the instances of each CGT candidate, which measures its utilization and observes its communication patterns with other task candidates.
Each CGT candidate whose utilization is adequate is designated as a task, and its communication with other tasks forms producer-consumer relationships.
Cyclebite exports a produce-consume task graph (or simply task graph) for the application - a directed acyclic graph where each node is a CGT and directed edges are communication between CGTs, pointing from producer to consumer.
I show that Cyclebite finds both important code that state-of-the-art (SoA) structuring techniques miss and rejects unimportant code that SoA structuring techniques erroneously include in the task graph.
I propose a CGT analysis and export tool, called Cyclebite-Template, that extracts the parallel execution pattern of each CGT in the exported Cyclebite task graph, and exports the task graph into a domain-specific language, which facilitates its transformation and optimization towards a target DSA.
Cyclebite-Template works on a low-level representation of each CGT, making its analysis agnostic to the syntactic definition of each task, while SoA task templates use higher-level representations that are not robust to differing syntactic task definitions.
Further, Cyclebite-Template supports the transformation and optimization of non-polyhedral tasks by extracting each task's canonical expression (which implies its parallel execution pattern), while SoA task templates only support polyhedral tasks.
I show that Cyclebite-Template accurately extracts the parallel pattern from Cyclebite tasks, and Cyclebite task graphs exported with Cyclebite-Template achieve speedups inline or exceeding those of SoA task templates.
ContributorsWillis, Benjamin Roy (Author) / Chakrabarti, Chaitali (Thesis advisor) / Brunhaver, John (Thesis advisor) / Shrivastava, Aviral (Committee member) / Zhang, Jeff (Committee member) / Arizona State University (Publisher)
Created2024
Description
Clustered regularly interspaced short palindromic repeats (CRISPR)-based DNA Adenine Base Editors (ABEs) represent a groundbreaking advancement in precision genome editing, holding great potential for treating human genetic diseases caused by single nucleotide polymorphisms (SNPs). ABE8e, the most efficient ABE to date, catalyzes the conversion of adenine to guanine, introducing targeted point mutations into genomic DNA. This technology leverages the fusion of CRISPR-Cas9 molecular machinery with a single-stranded DNA (ssDNA)-specific adenosine deaminase evolved from a bacterial tRNA-specific adenosine deaminase (TadA) through directed evolution. This interdisciplinary study, employing computational (molecular dynamics simulations and free energy simulations) and experimental [ensemble Förster Resonance Energy Transfer (FRET), thermal stability assessments, and in vitro activity assays] approaches, reveals the biophysical foundations underlying ABE8e’s 500-fold increase in DNA base editing efficiency compared to other generations. Here the key to this enhancement is shown to be the stable dimerization of the deaminase domain (TadA8e). Its strategic juxtaposition to Streptococcus pyogenes Cas9 (SpCas9) and DNA substrate is achieved via critical interactions involving residues in the TadA8e docking domain (R98 and R129), the residues in the RuvC domain of SpCas9 (E1046) and the phosphates in the backbone of the DNA substrate, uniquely established when TadA8e operates as a stable dimer. It is revealed that T111R and D119N in combination with N122H, mutations introduced to TadA during the evolution of ABE7.10 to ABE8e, drive TadA8e dimerization and enhance DNA editing efficiency of ABE8e. However, ABE8e’s dimerization and aggregation hinder its delivery to the cell using cell-penetrating peptides (CPPs). Thus, a monomeric form of ABE8e is engineered by disrupting the hydrophobic dimerization interface of TadA8e using the QTY code, however, the TadA8e dimers persisted. Ongoing computational simulations aim to identify additional critical residues for efficient disruption of TadA8e dimer.Overall, these findings illuminate the molecular mechanisms driving ABE8e’s improved performance and suggest new engineering strategies aimed at mitigating off-target effects, enhancing editing efficiency, and streamlining cell delivery processes all of which are crucial for the therapeutic application of precision genome editors.
ContributorsCHEN, XIAOYU (Author) / Lapinaite, Audrone AL (Thesis advisor) / Levitus, Marcia ML (Committee member) / Stephanopoulos, Nicholas NS (Committee member) / Arizona State University (Publisher)
Created2024
Description
Traditional approaches to bio-inspired design typically begin with a problem statement, followed by a search for a biological analog in nature, and then creating a design inspired by the underlying design principle embodied in the analog. Although this method results in some breakthrough innovations, it has two fundamental limitations. Firstly, identifying a design principle is often based on a biological understanding of the specific structure-function relationship of interest, with limited study of its generalization beyond the context in which it evolved. This leaves several potential design principles off the table and may result in sub-optimal design. The second limitation of traditional bio-inspired design is the ad-hoc way it is implemented in the engineering design process, making scalability and reproducibility by others in the engineering community challenging. Despite the enormous potential of leveraging the rich information embedded in biological form and the rising interest in bio-inspired design, there is no generalized, accessible computational design tool that enables it. This thesis addresses this limitation systematically; the first limitation is addressed with a new methodology proposed called "bio-morphism to biomimetic design." This methodology encourages the designer to gather in-depth knowledge about the organism's biology and its environment; this allows the designer to identify the design feature and test design principles contextually. As the name suggests, this is first done in a closer contextual reference to the organism (bio-morphism). Then, post-validation is extended to more generalizable design principles (biomimetic design). The second limitation is addressed by developing a computational tool for the biomimetic design called "BioMotif." It integrates mathematical, biological, and physical models, which are repeatable and efficient. This tool aims to make the transition from analogies in nature to CAD design easy, smooth, and repeatable. The approach is demonstrated for two types of discrete structural elements: network materials and branches. Euplectella Aspergillum, also known as the Venus Flower Basket (VFB), was the organism used in the study of network materials, and a variety of branching structures like river deltas, tree architectures, and vascular branching structures were used as analog organisms for branching.
ContributorsMistry, Yash (Author) / Bhate, Dhruv (Thesis advisor, Committee member) / Chawla, Nikhilesh (Committee member) / Li, Xiangjia (Committee member) / Nian, Qiong (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2024